Soft anchors with soft eyelets

ABSTRACT

Soft anchor constructs and methods for soft tissue to bone repairs. The soft anchors may be knotted or knotless constructs. The soft anchors include a body formed of various soft materials (including, but not limited to, suture) and provided in various shapes and configurations that confer the anchors the ability to be easily inserted within bone tunnels or sockets and be bunched up within the bone tunnels or sockets. At least one closed loop or soft eyelet is attached to the soft anchor to allow additional sliding strands and/or shuttle/pull devices (suture passing devices) to pass through the eyelet and aid in the knotted or knotless fixation of tissue to bone.

CROSS-REFERENCE TO RELATED APPLICATIONS

This is a divisional of U.S. patent application Ser. No. 13/961,716,filed Aug. 7, 2013, which claims the benefit of U.S. ProvisionalApplication No. 61/684,418 filed Aug. 17, 2012, the disclosures of whichare incorporated by reference in their entireties herein.

FIELD OF THE INVENTION

The present invention relates to surgical devices and, in particular, tosoft suture-based anchors.

BACKGROUND OF THE INVENTION

When soft tissue such as a ligament or a tendon becomes detached from abone, surgery is usually required to reattach or reconstruct the tissue.Often, a tissue graft is attached to the bone to facilitate regrowth andpermanent attachment. Techniques and devices that have been developedgenerally involve tying the soft tissue with suture to an anchor or ahole provided in the bone tissue. Knotless suture anchors, such as thetwo piece Arthrex PushLock® anchor, disclosed in U.S. Pat. No.7,329,272, have been developed to facilitate tissue fixation to bone.

It would be desirable to provide a suture construct that may be knottedor knotless and that is formed essentially of a soft material such assuture (or suture-based materials or other soft materials and/orcompositions) with the ability to be inserted into a bone socket butalso having tying, sliding sutures that are allowed to run/slide freely.Also needed is a soft, suture-based anchor that is knotless and isprovided with an independent, soft suture eyelet and a self-cinchingmechanism connected to both the independent, soft suture eyelet and tothe suture-based anchor.

SUMMARY OF THE INVENTION

The present invention provides soft anchors which are designed to beinserted into the bone and which have flexible strand(s) within the bodyof the anchors. The soft anchors may be knotted or knotless constructs.The soft anchors include a body formed of various soft materials(including, but not limited to, suture) and provided in various shapesand configurations that confer the anchors the ability to be easilyinserted within bone tunnels or sockets and be bunched up within thebone tunnels or sockets. At least one closed loop or soft eyelet isattached to the soft anchor to allow additional sliding strands and/or ashuttle/pull device (suture passing device) to pass through the eyeletand aid in the knotted or knotless fixation of tissue to bone.

These and other features and advantages of the invention will be moreapparent from the following detailed description that is provided inconnection with the accompanying drawings and illustrated exemplaryembodiments of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates a soft anchor according to an exemplary embodiment ofthe present invention.

FIG. 2 illustrates the soft anchor of FIG. 1 with at least one slidingsuture passing through the eyelet of the anchor.

FIGS. 3 and 4 illustrate additional views of the soft anchor of FIG. 1(showing the positioning of the eyelet relative to the body of theanchor).

FIG. 5 illustrates a soft anchor according to another exemplaryembodiment of the present invention (with a self-cinching loop passedaround tissue and attached to the body of the anchor).

FIGS. 6-11 illustrate subsequent steps of a method of forming the softanchor of FIG. 5 (with a self-cinching construct) and of employing thesoft anchor for attachment of soft tissue to bone.

FIG. 12 illustrates a soft anchor according to another exemplaryembodiment of the present invention.

FIG. 13 illustrates the soft anchor of FIG. 12 with at least one slidingsuture passing through the eyelets of the anchor and secured to aninserter instrument.

FIGS. 14 and 15 illustrate steps of forming a soft anchor according toyet another exemplary embodiment of the present invention (a knotlesssoft suture with a self-cinching loop).

FIGS. 16-20 illustrate subsequent steps of a method of attaching softtissue to bone with the soft anchor of FIG. 15 and according to anexemplary embodiment of the present invention.

FIG. 21 illustrates an exemplary embodiment of an inserter of thepresent invention.

DETAILED DESCRIPTION OF THE EMBODIMENTS

The present invention provides surgical systems and methods for knottedor knotless soft tissue (ligament, tendon, graft, etc.) repair andfixation, such as fixation of soft tissue to bone. The surgical systemsof the present invention include fixation devices in the form of softanchors that are formed of various soft materials and are provided invarious shapes and configurations that confer the anchors the ability tobe easily inserted within bone tunnels or sockets and be bunched upwithin the bone tunnels or sockets. The soft anchors are formedessentially of soft materials such as yarns, fibers, filaments, strings,fibrils, strands, sutures, etc. or combinations of such soft materials.The soft materials may be synthetic or natural materials, orcombinations of synthetic and natural materials, and may be degradableor non-degradable or combinations thereof.

At least one closed loop or soft eyelet is attached to the body of theanchor to allow additional sliding flexible strands and/or shuttle/pulldevices (suture passing devices) to pass through the eyelet and aid inthe fixation of tissue to bone.

The soft anchors may be knotted or knotless. As detailed below, anexemplary knotted soft anchor includes (i) an anchor body, (ii) asecuring strand that extends through at least a portion of the body andforms a closed loop and/or at least one soft eyelet, and (iii) a tissueattachment strand (knot tying suture) that attaches to the closed loopand/or the at least one soft eyelet, and secures the tissue to befixated by having knots tied in.

As detailed below, an exemplary knotless soft anchor includes (i) ananchor body, and (ii) a securing strand that extends through at least aportion of the body, the securing strand having, at one end, a closedloop and/or at least one soft eyelet and, at a portion of the other end,a self-cinching assembly (a spliced loop). The self-cinching assembly(splice loop) may be formed with a shuttle/pull device (for example, asuture passing instrument such as a wire suture passer) attached to theconstruct.

The anchors have a body in the form of any sleeve/sheath structure whichmay be provided with open or closed ends, or with at least one open endor with at least one opening on the side of the body for the securingstrand to exit the body on a sidewall of the body (i.e., not at the endof the body). The anchors may also have a tubular shape, partiallytubular shape, or may be in the form of a hollow shape construct. Theanchors have a body which may be a woven, braided or knitted structure,and/or may be formed of yarns, fibers, filaments, sutures or similarmaterials, or combinations of such materials. The anchor body istypically without a core. In exemplary-only and non-limitingembodiments, the soft anchors include a body that is formed essentiallyof suture. The suture-based anchor body may be any woven, braidedstructure including, but not limited to, suture formed of polyester,polyethylene or any other suture material. If the anchor is knotless,the securing strand is preferably formed of a coreless suture toaccommodate the splicing.

The securing strand that attaches to the anchor body may be any typesuture, including coreless sutures that form a closed loop, or twoeyelets each at one end of the strand (i.e., in a dumbbell shape), or aneyelet at one end and a shuttle/pull device (a suture passing instrumentsuch as a wire suture passer) at the other end to form a spliced loop.The securing strand can extend through the open ends of thesleeve/sheath or through an opening in the sleeve body. Once the anchorbody is inserted into a bone tunnel or socket it bunches up securing theanchor in the tunnel. The securing strand does not necessarily have tobe engaged to accomplish the bunching of the anchor.

The tissue attachment strand may be any flexible strand (for example,suture) and may be pre-assembled to hold the anchor onto an inserter.The tissue attachment strand is the strand that attaches to the tissueand gets knots tied in it, and that also holds the construct to aninserter instrument to keep the construct at the bottom of the bonehole/socket. For the knotless anchors, and as described below, thesecuring strand becomes the tissue attachment strand (this strand doesnot require a knot to secure the tissue, the splice accomplishes thelocking). For the knotless anchors, an attachment suture is used to holdthe anchor onto the inserter during the insertion process and thenremoved once the anchor is in the bone hole/socket.

Referring now to the drawings, where like elements are designated bylike reference numerals, FIGS. 1-20 illustrate exemplary soft anchors100, 200, 100 a, 200 a of the present invention that are formedessentially of a flexible, soft material such as suture (for example, apolyester sheath) or any other similar soft materials. Soft anchor 100and 100 a are exemplary knotted embodiments. Soft anchors 200 and 200 aare exemplary knotless embodiments.

FIGS. 1-4 illustrate soft anchor 100 formed essentially of anchor body10 in the form of a flexible material 10 (for example, a braided suturesuch as a polyester sheath/sleeve/tube 10) and a securing strand 11which forms a soft independent closed loop 15 attached to the anchorbody 10. Closed loop 15 may be formed by tying a knot or splicing. Forexample, FIGS. 3 and 4 show closed loop 15 formed by splicing whileFIGS. 1 and 2 show the closed loop formed by providing knot 12 at thetop in the middle of the U-shaped structure. The anchor body 10 may bein the form of any sleeve/sheath structure or tubular structure whichmay be provided with open or closed ends 10 a, 10 b (FIG. 1), or with atleast one open end or with at least one closed end. The anchor body 10may be a woven, braided or knitted structure, and/or may be formed ofyarns, fibers, filaments, sutures or similar materials, or combinationsof these materials, including, but not limited to, suture formed ofpolyester.

Securing strand 11 is a flexible strand that is passed through at leasta portion of the length of the flexible material 10. The securing strand11 attaches to the anchor body 10 and may be any type of suture,including coreless sutures that form closed loop 15. The securing strand11 can extend through the open ends 10 a, 10 b of the sleeve/sheath 10or through an opening in the sleeve body. The securing strand 11 mayassist in bunching up the anchor body 10 (sleeve/sheath) once the anchorbody 10 is inserted into a bone tunnel or socket. The securing strand 11may be also attached to the anchor body 10 in a suture-through-suturetechnique (with a needle, for example). Strand 11 may be an exemplaryFiberWire® or TigerWire® suture 11, and may circle back to exit throughthe sheath 10, creating a closed independent loop/eyelet 15. The strandforming the closed loop/eyelet 15 exits on one side of the anchor bodyand enters on the other side of the anchor body, so that there is a gapin the anchor where the closed loop is exposed. Loop/eyelet 15 is a softloop/eyelet. In an exemplary-only embodiment, the securing strand 11(the FiberWire® or TigerWire® suture 11) may be passed through theanchor body 10 at different locations and as desired, for example, atpredetermined insertion points on the length of the anchor body. The endof the FiberWire® or TigerWire® suture 11 is brought back to reenter theanchor body 10 to form the closed loop 15.

FIG. 2 illustrates soft anchor 100 with at least another flexible strand40 (a tissue attachment strand 40) passing through the closed loop 15.The tissue attachment strand 40 may be any flexible strand (for example,suture) and may be pre-assembled with the anchor on an inserter (similarto inserter 60 shown in FIG. 13). The tissue attachment strand 40 is thestrand that attaches to the tissue to get fixated/reapproximated andgets knots tied in it (and also holds the construct to the inserter tokeep the construct at the bottom of the bone hole/socket).

When the soft anchor 100 is inserted into a bone socket/tunnel employingan inserter instrument (for example, a pusher provided with a forkedtip), the body of the anchor 100 bunches up within the bonesocket/tunnel. However, the tissue attachment suture 40 remains free toslide untangled, to allow completion of the soft tissue repair, forexample, to be passed through or around the soft tissue to be attachedto the bone.

FIGS. 3 and 4 illustrate additional views of the soft anchor 100 of thepresent invention showing in more detail the securing strand 11 formingspliced closed loop 15 contained within the body of the exemplary sheath10 (tubular construct 10).

A method of tissue repair with the exemplary construct 100 (soft knottedanchor 100) of the present invention comprises inter alia the steps of:(i) drilling/punching a hole in bone; (ii) inserting soft anchor 100into the hole in the bone to compress the soft anchor into the hole; and(iii) tying free suture 40 around or through tissue and completing therepair tying knots.

FIG. 5 illustrates another embodiment of the present invention. Softanchor 200 is similar to the soft anchor 100 in that it also contains ananchor body 10 formed essentially of a soft material (for example,coreless suture such as a UHMWPE braided sheath/sleeve) and a securingstrand 11 forming soft independent loop 15 attached to anchor body 10.However, the soft anchor 200 is a knotless—and not knotted—constructthat contains a self-cinching construct 50 attached to the loop 15 (andto the braided sheath 10), as shown in FIG. 5. The self-cinchingconstruct 50 may be formed prior or after the lodging of the soft anchorinto bone, and eliminates the formation of any knots and the need for atissue attachment strand (such as strand 40 of FIG. 2).

Self-cinching construct 50 may be formed by passing a length of flexiblematerial 51 (for example, a cinching suture 51) through the length ofthe anchor body 10 (braided sheath/sleeve 10) two times with a needle,as shown in FIG. 5. The ends of strand 51 are then tied together to forma knot 52, closed loop 54 and closed loop 15 (both loops having asimilar perimeter). The perimeter of loop 54 is fixed.

One end of the strand 51 is then passed through the loops 15, 54 andaround (or through) tissue to be fixated, and then spliced through theremaining end, to form splice 53 and adjustable cinching loop 55 (shownin FIG. 5). The perimeter of cinching loop 55 is adjustable, to allowthe construct to be self-cinching and to adjust the tension on thetissue to be fixated.

The assembly created by the cinching loop 55 uses the suture loop 15(eyelet 15) as a turning point for application of force and to directthe cinching suture 51 into the construct in the correct manner.

FIGS. 6-11 illustrate details of forming the self-cinching construct 50with cinching loop 55 of soft, knotless anchor 200 and methods ofattaching tissue to bone by employing such construct. FIGS. 6-8illustrate in more detail the splicing of the cinching suture 51, at thesplice region 53. FIG. 9 illustrates the insertion of soft, knotlessanchor 200 into drilled hole 99 formed within bone 90. FIGS. 10 and 11illustrate the self-cinching construct 50 with cinching loop 55 of soft,knotless anchor 200 passed around tissue 95 which is to be secured tobone 90. By pulling on the free end of the cinching suture 51, theperimeter of the adjustable, cinching loop 55 decreases around thetissue 95 and approximates the tissue 95 to bone 90, at the desiredlocation and under the desired tension.

FIGS. 12 and 13 illustrate yet another exemplary embodiment of a softanchor 100 a of the present invention. Soft anchor 100 a is similar tothe soft anchor 100 of FIGS. 1-4 in that it is also a knotted anchor(i.e., allows attachment of a tissue attachment strand that will securetissue by tying knots) but differs in that the securing strand 11 formstwo small eyelets/loops 15 a, 15 b that allow tissue attachment strand40 to attach thereto and pass slidingly there through. Anchor body 10 ofsoft anchor 100 a is similar to anchor body 10 of anchor 100 in that itis also formed essentially of a soft material (for example, corelesssuture such as a polyester braided sheath/sleeve) that may have asleeve/sheath/tubular configuration with open or closed ends and/or maybe a hollow construct. Anchor body 10 of soft anchor 100 a may be anywoven, knitted, or braided structure formed of various yarns, fibersand/or filaments, and typically without a core.

Securing strand 11 could be any type of suture (including corelesssuture) that has a dumbbell configuration with two small eyelets 15 a,15 b (as shown in FIG. 12). Strand 11 can extend through the cannulationof the sleeve/sheath 10 and through the open ends 10 a, 10 b, or throughan opening in the sleeve body 10. The securing strand 11 accommodatesthe tissue attachment strand 40.

FIG. 13 illustrates tissue attachment strand 40 passed through eyelets15 a, 15 b of securing strand 11 and further secured to inserter 60(pre-assembled with the anchor to inserter 60). Strand 40 attaches tothe tissue to be fixated and forms knots for securing the tissue repairfor the knotted embodiments. A more detailed depiction of inserter 60 isshown in FIG. 21.

FIGS. 14 and 15 illustrate yet another embodiment of soft anchor 200 aof the present invention. Anchor 200 a is similar to soft anchor 200 ofFIG. 5 in that it is also a knotless soft anchor which has an anchorbody 10 similar to anchor body 10 of soft anchor 200. However, anchor200 a differs from anchor 200 in that the securing strand 11 is providedwith only one eyelet 15 a (located at one end of the strand) andpreloaded with a shuttle/pull device 70 (a suture passer 70 such as anitinol passing wire 70) attached at the portion of the strand thatexits the anchor body (for example, at a portion of the other end of thestrand). Suture passer 70 is pre-assembled to the securing strand 11 asshown in FIG. 14 and will form a splice loop 55 a shown in FIG. 15during the repair. Securing strand 11 could be any flexible strand suchas suture or suture tape, preferably without a core to make the spliceeasier. The securing strand 11 becomes the tissue attachment suture, butwithout requiring a knot to secure the tissue since the spliceaccomplishes the locking. An attaching suture is also attached to theanchor to provide for pre-assembly of the construct to the inserter 60.The attaching suture is removed once the anchor is placed in the bonehole/socket.

The free end 11 a of strand 11 is passed through eyelet 71 of the suturepasser 70 (in the direction of arrow A of FIG. 14) and then the suturepasser 70 is pulled to allow strand 11 to pass through itself at theregion 53 (FIG. 15) and form splice 53 and self-cinching adjustableflexible loop 55 a (FIG. 15). The perimeter of flexible loop 55 a isadjustable, to allow the construct to be self-cinching and to adjust thetension on the tissue to be fixated.

An exemplary knotless method of fixation of soft tissue to bone withsoft anchor 200 a of the present invention comprises inter alia thesteps of: (i) after insertion of anchor 200 a and removal of inserter60, suture 11 is passed around or through tissue 95 desired to be fixed;(ii) next, free end 11 a of strand 11 is fed through wire eyelet 71;(iii) wire end 72 is pulled which causes the construct to be created bycausing the free end 11 a of strand 11 to pass through eyelet 15 a,followed by the free end 11 a of strand 11 to pass through splice area53 and form adjustable knotless closed loop 55 a; and (iv) wire 70 isdiscarded and the free end 11 a of strand 11 is tensioned to desiredrepair approximation.

FIGS. 16-20 illustrate subsequent steps of a method of tissue fixation(tissue approximation/repair) with exemplary soft anchor 200 a of thepresent invention. Inserter 60 (FIG. 16) pushes soft anchor 200 a withinbone hole 99 formed in bone 90. FIG. 17 shows the sheath 10 (anchor body10) bunched up within the bone hole 99, i.e., from a non-compressed,initial length L₁ (FIG. 16) to a compressed, bunched up, final length L₂(FIG. 17).

Soft anchor 200 a is provided pre-assembled with shuttle/pull device 70(nitinol passing wire 70) attached to strand 11 (at splice area 75) andpassing through eyelet 15 a. Free end 11 a of strand 11 is passedthrough the nitinol wire eye 71 (in the direction of arrow A) and aroundexemplary soft tissue 95 to be attached to bone 90, as shown in FIG. 17.Tensioning on the wire end 72 pulls the suture end 11 a through theconstruct (FIG. 18).

Wire passer 70 is removed and tension is applied on the suture end 11 aof strand 11, as shown in FIG. 19 (by pulling in the direction of arrowB) to form adjustable closed loop 55 a that is tightened on and aroundtissue 95. FIG. 20 illustrates final repair 300 with sheath 10 (anchorbody 10) bunched up within the bone hole 99 and securing strand 11around soft tissue 95 approximated to bone 90 by adjustable, knotlessself-cinching flexible spliced loop 55 a.

The materials employed for the formation of the soft anchors 100, 200,100 a, 200 a may be loosely braided polyester sutures, which may bebraided with at least one other fiber, natural or synthetic, to formlengths of suture material. The suture-based anchors 100, 200, 100 a,200 a may be also formed of suture tape. The suture tapes may have thesame, uniform width or may have different widths, and may comprise thesame or different materials.

The flexible, soft material forming the soft anchors 100, 200, 100 a,200 a may be also formed of suture tape or a combination of suture andtape, a stiff material, or combination of stiff and flexible materials,depending on the intended application. Alternatively, the flexiblematerial may be formed in the shape of a folding tube suture anchorwhich may contain textile or homogenous material. The folding tubeanchor may be formed of a tube (cylinder or sleeve/sheath) provided withapertures/holes to allow the flexible strands to pass therethrough. Whenthe tube is inserted into a bone tunnel/socket and when tension isapplied, the tube folds and lodges into the bone tunnel/socket but thetying, sliding sutures remain free for additional manipulation andsurgical procedures.

As noted above, the soft anchors 100, 200, 100 a, 200 a may be formed ofany soft materials such as yarns, fibers, filaments, strings, fibrils,strands, sutures, etc. or combinations of such soft materials. The softmaterials may be woven, braided, knitted or otherwise interlocked witheach other to achieve the soft anchors of the present invention. Thesoft materials may be synthetic or natural materials, or combinations ofsynthetic and natural materials. The anchors 100, 200, 100 a, 200 a maybe in the form of any sleeve/sheath/tubular structure which may beprovided with open or closed ends, or with at least one open end or withat least one closed end. The anchors 100, 200, 100 a, 200 a may alsohave a tubular or cylindrical shape, partially tubular shape, asleeve-like shape, or may be in the form of any hollow or partiallyhollow shape construct provided with a cannulation extending at leastalong a portion of the length of the structure. The anchors 100, 200,100 a, 200 a may be woven or braided structures, or may be formed ofyarns, fibers or similar materials, or combinations of these materials,that are joined/interlocked together by any known method in the art. Inthe exemplary-only embodiments above, the soft anchors 100, 200, 100 a,200 a of the present invention are suture-based anchors formedessentially of suture such as braided polyester or polyethylene.

As noted above, the soft anchors 100, 200, 100 a, 200 a detailed abovemay be also employed with a self-cinching suture mechanism that could beincorporated into the implant/anchor. Once the anchor is deployed, thesurgeon would simply pull on the self-cinching suture strands to firmlysecure the device and compress the tissue (for example, the rotatorcuff). The soft anchors 100, 200, 100 a, 200 a could be utilized formultiple additional indications such as, for example, AC jointreconstruction, syndesmosis reconstruction, quad/patellar tendon rupturerepair, hallux-valgus repair, and any other tendon repair to bone.

The soft anchors 100, 200, 100 a, 200 a detailed above may be alsoemployed in conjunction with additional various knotted and/or knotlessfixation devices (or combination of such knotted and knotless fixationdevices), such as hard suture anchors to secure, for example, a medialrow on rotator cuff repairs.

The flexible strands 11, 40 employed for the formation of the softanchors 100, 100 a, 200, 200 a may be high-strength sutures, such as thehigh strength suture sold by Arthrex, Inc. of Naples, Fla. under theregistered tradename TigerWire® or FiberWire®, which is disclosed andclaimed in U.S. Pat. No. 6,716,234, the entire disclosure of which isincorporated by reference in its entirety herewith. FiberWire® suture isformed of an advanced, high-strength fiber material, namely ultrahighmolecular weight polyethylene (UHMWPE), sold under the tradenamesSpectra (Honeywell) and Dyneema (DSM), braided with at least one otherfiber, natural or synthetic, to form lengths of suture material. Thepreferred FiberWire® suture includes a core within a hollow braidedconstruct, the core being a twisted yarn of UHMWPE.

The flexible strands may be also formed of suture tape or a suturechain. The suture tapes may have the same, uniform width or may havedifferent widths, and may comprise the same or different materials.

Although the present invention has been described in connection withpreferred embodiments, many modifications and variations will becomeapparent to those skilled in the art. While preferred embodiments of theinvention have been described and illustrated above, it should beunderstood that these are exemplary of the invention and are not to beconsidered as limiting.

What is claimed is:
 1. A soft anchor for surgical repairs comprising: ananchor body consisting essentially of a flexible material designed to becompressed from a first, non-compressed position to a second,compression position; at least one flexible strand attached to theanchor body, the flexible strand forming a closed loop or at least oneeyelet; and a tissue attachment strand passed through the closed loop orthrough the at least one eyelet.
 2. The soft anchor of claim 1, furthercomprising a tensionable construct attached to the flexible strand. 3.The soft anchor of claim 2, wherein the tensionable construct is aself-cinching adjustable closed loop having an adjustable perimeter. 4.The soft anchor of claim 2, wherein the tensionable construct is formedby providing a shuttling device attached to a portion of the flexiblestrand that exits the anchor body.
 5. The soft anchor of claim 1,wherein the at least one flexible strand is provided with two eyelets,each at one end of the flexible strand, and wherein the anchor furthercomprises a tissue attachment strand slidingly passing through the twoeyelets.
 6. A soft anchor comprising: a tubular sleeve or sheath formedof a flexible material and having a first length, a cannulation and twoends; an eyelet at one of the two ends of the tubular sleeve or sheath;and a suture passing device at the other of the two ends of the tubularsleeve or sheath.
 7. The soft anchor of claim 6, wherein the suturepassing device forms a flexible, adjustable, closed loop attached to theeyelet, the flexible, adjustable, closed loop having an adjustableperimeter and being self-cinching.
 8. The soft anchor of claim 6,wherein the flexible, adjustable, closed loop surrounds soft tissue tobe approximated to bone and, when tensioned, allows correctapproximation of the soft tissue to the bone.
 9. A method of knottedfixation of soft tissue to bone, comprising the steps of: providing asoft anchor comprising a tubular sleeve or sheath formed of a flexiblematerial and having a first length, a cannulation and two ends; aflexible strand attached to the tubular sleeve, the flexible strandforming a closed loop or at least one eyelet; and a tissue attachmentstrand passed through the closed loop or the at least one eyelet;inserting the soft anchor into a tunnel or socket in a bone to bunch upthe tubular sleeve or sheath within the tunnel or socket and to wedgethe tubular sleeve or sheath within the tunnel or socket; pulling onends of the tissue attachment strand; and tying at least one knot withthe tissue attachment stand around soft tissue to be fixated to thebone.
 10. The method of claim 9, wherein the flexible material of thetubular sleeve or sheath is a suture.
 11. The method of claim 10,wherein the flexible material of the tubular sleeve or sheath is acoreless braid of polyester.
 12. The method of claim 9, wherein thetissue attachment strand is a sliding suture which freely slides withinthe closed loop or at least one eyelet even after the step of bunchingup the tubular sleeve or sheath within the tunnel or socket.